Set the number of digits after the point in double

In c# double type how can i set the number of digits after the point, i need o开发者_如何学编程nly 4. thank you.

You can't. Binary floating point doesn't work like that. You can format a double that way (e.g. using "f4" as the format string), but if you're dealing with values which have a natural number of decimal places, then you should probably be using decimal instead. Could you give us more information about what your values represent?

You can't set the number of digits after the point on the double directly.

You can change the string representation of the double using a format string.

One example would be:

string.Format("{0:0.####}", number);

Or as Jon Skeet points out:

number.ToString("f4")

Use this to compare two floating point numbers to 4 digits in the fraction:

  if (Math.Abs(a - b) < 1E-4) {
    // close enough
    //...
  }